Threading device for a sewing machine



March 24, 1970 SUSUMU HANYU 3,502,045

THREADING DEVICE FOR A SEWING MACHINE Filed Sept. 6. 1967 5 Sheets-Sheet 1 Wmlnann INVENTOR. $4 M a Ham March 24, 1970 SUSUMU HANYU THREADING DEVICE FOR A SEWING MACHINE 3 Sheets-Sheet 2 Filed Sept. 6. 1967 INVENTOR. $44 2 [11 a f/ w March 24, 1970 susuMu HANYU 3,502,045

THREADING DEVICE: FOR A SEWING MACHINE Filed Sept. 6. 1967 3 Sheets-Sheet 3 INVENTOR. \fhx uha 91 United States Patent 0 l 3,502,045 THREADING DEVICE FOR A SEWING MACHINE Susumu Hanyu, Tokyo, Japan, assignor t0 Janome Sewing Machine Co., Ltd., Tokyo, Japan Filed Sept. 6, 1967, Ser. No. 665,807

Claims priority, application Japan, Sept, 7, 1966,

41/83,806 lint. Cl. D051) 87/02 US. Cl. 112-225 19 Claims ABSTRACT OF THE DISCLOSURE A stationary guide casing is mounted on the presser bar of a sewing machine and guides 21 second guide casing in which a threading member with a hook is guided. When manual pressure is applied to the threading member, the movable guide casing engages the needle and positions the threading hook whereupon a spring is compressed by the manual pressure and the threading hook is inserted into the needle eye.

BACKGROUND OF THE INVENTION The threading the needle of a sewing machine is not easy, since the needle is fixed to the sewing machine and often has a very small eye. A great number of threading devices for sewing machines are known, which are either rather bulky and take up a great deal of space, or are out of proportion to the fine needle which is to be threaded. Other prior art constructions which are of a simple construction, are not entirely reliable to accomplish the threading of the needle.

SUMMARY OF THE INVENTION It is one object of the invention to provide a threading device of simple construction which takes up little space in the region of the needle bar and reliably and smoothly accomplishes the threading operation Without any damage to the thread or needle.

Another object of the invention is to provide a sewing machine with a threading device all parts of which are guided for movement in the same direction toward and away from the needle.

Another object of the invention is to provide a sewing machine with a threading device whose threading hook is completely withdrawn into a casing in the normal inoperative condition of the device, so that neither cloth, nor thread, nor the finger of the operator can be caught by the hook.

With these objects in view, one embodiment of the invention comprises holding means mounted on the sewing machine, preferably on the presser bar, guide means mounted on the holding means, preferably in a casing portion, for movement between an inoperative position and an engaging position engaging and being adjusted by the needle of the sewing machine, threading means mounted on the guide means for movement relative to the same, and preferably including a manually operable member and a threading hook pivotally mounted on the same, first spring means connecting the guide means with the holding means and opposing movement of the guide means to the engaging position with a first resilient force, and second spring means connecting the threading means With the guide means and opposing movement of the threading means to an advanced position with a second resilient force greater than the first resilient force.

When manual pressure is applied to the threading means, the guide means moves to the engaging position so that the threading means is aligned with the needle eye,

3,502,045 Patented Mar. 24, 1970 whereupon continued manual pressure moves the threading means relative to the guide means to the advanced position so that the threading means passes through the needle eye, ready to receive a thread. Upon release of the threading means by the operator, the threading means and the guide means are retracted by the respective springs, and preferably completely enveloped by the casing portion of the holding means.

In the preferred embodiment of the invention, the casing portion of the holding means is tubular and has a rectangular cross section, and the guide means is a tubular casing of matching rectangular cross section slidably guided in the stationary casing portion of the holding means. The manually operable member of the threading means is guided in the guide casing, while the threading hook, which is pivotally connected with the manually operable member, can perform an angular movement. This facilitates the insertion of the threading hook into the needle eye, since in the event that the needle hook does not exactly meet the center of the eye, it is guided by the needle portions surrounding the eye into the same while pivoting a small angle. While the threading opera ion is carried out in the upper dead center position of the needle bar and needle, the precise position of the needle eye cannot be determined with certainty, and consequently the pivotal support of the threading hook facilitates the insertion into the needle eye considerably.

The first spring means is a tension spring withdrawing the guide easing into the casing portion of the holding means, and the second spring is a compression spring urging the threading hook into the guide casing so that all parts are withdrawn, and the threading hook cannot catch anything in the normal inoperative position of the device.

Preferably, the holding means are mounted on the presser bar of the sewing machine so that the position of all parts of the threading device in relation to the needle bar and needle is accurately determined. It is possible to mount the device in a position in which the casing portion of the holding means, the guide casing, and the threading means are all located in a position inclined to the axis of the presser bar and needle, and in a plane passing through the presser bar and needle bar. Consequently, the threading hook is retracted in upward direction and located spaced a great distance from the sewing area under the presser foot when not in use. To facilitate the entry of the threading hook into the needle eye, the hook portion of the threading member is bent and has a substantially horizontal position.

The novel features which are considered as characteristic for the invention are set forth in partcular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side view on a reduced scale, illustrating a sewing machine provided with the threading device of the invention;

FIG. 2 is a side view on a larger scale, partially in vertical section, and illustrating a threading device according to the invention;

FIG. 3 is a perspective view of the threading device;

FIG. 4 and FIG. 5 are side elevations, partially in vertical section, and illustrating two operational positions of the threading device; and

FIG. 6 is an exploded perspective view illustrating the threading device in disassembled condition.

3 DESCRIPTION OF THE PREFERRED EMBODIMENT A sewing machine is mounted on a bed 51 which has a fabric supporting surface 52 on which a presser foot 23 secured by a screw 3 to the lower end of the presser bar 1 is located.

All parts of the threaded device are mounted on a holding means 4 which has an arcuate attaching portion 5 partly embracing the cylindrical presser bar 1, and being attached to the same by a screw 25. Since the arcuate attaching portion 5 fits on the presser bar 1, turning of holding means 4 about the axis of attaching screw 25 is not possible.

As best seen in FIG. 6, holding means 4 has a tubular casing portion 8 of rectangular cross section, connected with attaching portion 5 by a plate which has an elongated recessed portion 24 of arcuate cross section.

When holding means 4 is attached to the presser bar, casing portion 8 extends at an acute angle to the presser bar 1 and to the needle 22, while the vertical plane of symmetry of easing portion 8 passes through the axis of the needle.

A guide means in the form of a tubular guide casing 9 of rectangular cross section is slidably guided in the holding portion 8. The end of guide casing 9 confronting the needle has a projecting engaging portion 10 with a triangular recess bounded by two slanted guide edges 10a. The other end of guide casing 9 has a flange 12. A stop portion 11 has a bore into which one end of a tension spring 21 is hooked. The other end of spring 21 is hooked into a bore 7 in the recessed portion 24 so that spring 21 is partly located and guided by recessed portion 24 whose arcuate configuration matches the spring. Spring 21 pulls guide casing 9 to a normal inoperative position shown in FIG. 2 in which stop portion 11 abuts the front end of casing portion 8.

The threading means include a manually operable member 14 which has a pushbutton 18 at one end, and has a slot 15 dividing its other end so that a threading member 16 can be inserted into the slot until a bore 26a is aligned with bores 14a in the two prongs of member 14. In this position, a pivot pin 17 is inserted through bores 14a and 26a, and also through slots 13 in the side walls of guide casing 9.

A compression spring 19 is mounted on member 14 abutting pushbutton 18 and flange 12 of guide casing 9.

Threading member 16 has a main portion located in guide casing 9, and a transversely projecting portion 26 slidingly engaging the inner surface of guide casing 9. Consequently, the main portion of the threading member 16 is inclined to the needle at substantially the same angle as the guide casing 9 and the casing portion 8 of holding means 4, but a small angular movement of threading member 16 within the guide casing is possible.

The free end of threading member 16 has a hook portion extending at an obtuse angle to the main portion of threading member 16, in a substantially horizontal direction, which facilitates the entry of the hook portion 20 into the needle eye 28.

A recess 29 is provided directly below the attaching portion 5 on the side of presser bar 1 remote from the needle. A projection 6 has a cutting edge bounding the lower portion of recess '29 so that when a thread is inserted into recess 29, the thread is cut.

In the normal inoperative position of the device shown in FIGS. 1, 2 and 3, compression spring 19 urges the threading means 18, 14, 16, 20 to a retracted position in which hook portion 20 is located within guide casing 9, and cannot catch a thread or the fabric or be touched by the finger of the operator. Guide casing 9 is also fully withdrawn by spring 21 so that engaging portion 10 is spaced from the needle, as best seen in FIG. 3. In this position, sewing operations are carried out, and since the device is spaced high above the surface 52 separated from the same by the presser foot 23, and also transversely spaced from the needle, it cannot interfere in any manner with the sewing operations.

When the threading of the needle 22 is desired, pushbutton 18 is pressed, and the manual force is transmitted by spring 19 to guide casing 9, and by spring 21 to the stationary holding means 4.

In accordance with the invention, the resilient force of the compression spring 19 is greater than the resilient force of the tension spring 21. Consequently, the manual pressure is first transferred through spring 19, without compressing the same, to the guide casing 9 Which moves forward against the action of spring 21 until the slanted guide edges 10a of engaging portion 10 engage opposite sides of the needle, as shown in FIG. 4. In this manner, the guide casing 9, and thereby the threading means 14, 16, are precisely placed in a plane passing through the axis of needle 22. At this moment, flange 12 abuts the end of casing portion 8 so that guide casing 9 cannot move further and deform needle 22.

Continued manual pressure on pushbutton 18 effects now compression of spring 19 so that member 14 moves into guide casing 9 and pushes threading member 16 to an advanced position in which hook portion 20 passes through the needle eye 28, as shown in FIG. 5.

This movement is terminated when the end portions of pivot pin 17 abuts the forward ends of the pair of slots 13 in the side walls of guide casing 9. As best seen in FIGS. 2 and 4, pivot pin 17 abuts the higher rear ends of slots 13 in the normal inoperative position since the manually operable member 14, 18 is urged by spring 19 away from guide casing 9.

Before the threading operation, needle 22 is placed in the upper dead center position so that the position of the needle eye 28 conforms to the position of the threading hook portion 20. The entry of hook portion 20 into the eye 28 is facilitated by the substantially horizontal position of the hook portion 20. In the event that the needle eye 28 is slightly displaced, the tip of hook portion 20 may engage the annular portion 28a which surrounds the needle eye 28, and since this portion is tapered toward the needle eye, the tip of hook portion 20 is guided into the needle eye which is possible since threading member 16 and hook portion 20 are mounted for pivotal movement on the manually operated threading member 14 by the pivot means 17.

In the threading position shown in FIG. 5, in which guide means 9, 10 is in the position engaging needle 22, and threading means 18, 14, 16, 20 is in a position advanced in relation to guide means 9, a thread is held in front of needle 22 and rearwardly of the hook of the threading means, whereupon the manual pressure on pushbutton 18 is relieved. Spring 19 expands and retracts the threading means so that the hook portion 20 draws the thread through the needle eye 28 until the threading hook 20 is in the position of FIG. 4. Thereupon, spring 21 will withdraw guide casing 9 to the position shown in FIG. 2, but if pushbutton 18 is momentarily released, the two movements will take place substantially simultaneously.

The sewing operations can now be started, and since the hook portion 20 and the guide casing 9 with engaging portion 10 are withdrawn, the threading device cannot interfere in any manner with the sewing operations. If cutting of a thread is desired, it is guided behind the presser bar 1 and inserted into recess 29 where it is cut by the cutting edge of projection 6.

FIG. 1 clearly shows the small size of the threading device as compared with the presser foot and the needle. Since the device is mounted on the presser bar, practically no space is taken up in the sewing region, and since pushbutton 18 is located rearwardly of the presser bar at the rear of the machine, it neither obstructs the view at the sewing area, nor the feeding of the fabric on the surface 52.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of threading devices for sewing machines differing from the types described above.

While the invention has been illustrated and described as embodied in a slanted threading device mounted on the presser bar of a sewing machine and having a pivotally mounted threading hook, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. In combination with a sewing machine having a needle with an eye, a threading device comprising holding means fixedly mounted on said sewing machine; guide means mounted on said holding means for movement in one direction between an inoperative position, and an engaging position engaging said needle; threading means mounted on said guide means for movement relative to the same in said one direction between a retracted position and an advanced position; first spring means conmeeting said guide means with said holding means and opposing movement of said guide means to said engaging position with a first resilient force; and second spring means connecting said threading means with said guide means and opposing movement of said threading means to said advanced position with a second resilient force greater than said first resilient force so that manual pressure on said threading means is transferred by said second spring means from said threading means to said guide means without deforming said second spring means, and moves said guide means to said engaging position whereby said threading means in said retracted position is aligned with said eye, so that continued manual pressure on said threading means deforms said second spring means and moves said threading means relative to said guide means to said advanced position whereby said threading means assumes a threading position passing through said eye.

2. A threading device as claimed in claim 1 wherein said threading means has a first straight guide way for guiding said guide means in said one direction; and wherein said guide means has a second straight guide way for guiding said threading means in said one direction.

3. A threading device as claimed in claim 2 wherein said first and second guide ways have a common axis.

4. A threading device as claimed in claim 1 wherein said first spring means is a tension spring; wherein said threading means has a manual pushbutton at the end thereof remote from said needle; and wherein said second spring means is a compression spring abutting said manual pushbutton and said guide means.

5. A threading device as claimed in claim 1 wherein said guide means has at one end an engaging portion for engaging said needle and at the other end a stop portion for engaging said holding means in said engaging position of said guide means whereby continued manual pressure on said threading means cannot displace said guide means from said engaging position and deforms said second resilient means so that said threading means is moved to said advanced position.

6. Threading device as claimed in claim 1 wherein said threading means include a manually operable member guided in said guide means, a threading member adapted to pass through the needle eye, and pivot means for mounting said threading member on said manually operable member so that said threading member is angularly adjusted and guided into said eye upon contact with the portion of said needle surrounding said eye.

7. Threading device as claimed in claim 6 wherein said guide means has walls for guiding said manually operable member and formed with slots; and wherein said pivot means includes a pivot pin guided in said slots during movement with said manually operable member of said threading means and engaging first ends of said slots under the action of said first spring means in said retracted position, and second ends of said slots in said advanced position under the action of manual pressure.

8. Threading device as claimed in claim 6 wherein said holding means includes a casing portion inclined to said needle at an acute angle, and guiding said guiding means therein for movement between said inoperative and engaging positions; and wherein said threading member has a main portion slidable on said guide means and being inclined to said needle at substantially the same angle as said casing portion and guide means, and a hook end portion projecting at an angle to said main portion and extending substantially at right angles to said needle.

9. Threading device as claimed in claim 8 wherein said main portion of said threading member has a transversely projecting portion in sliding contact with said guide means.

10. Threading device as claimed in claim 1 wherein said sewing machine includes a presser bar; and wherein said holding means includes an attaching portion embracing said presser bar and fitting on the same, attaching screw means for attaching said attaching portion to said presser bar, and a casing portion for guiding said guide means between said inoperative and engaging positions.

11. Threading device as claimed in claim 1 wherein said guide means has a free end portion formed with a recess bounded by two slanted edges for engaging opposite sides of said needle in said engaging position whereby the position of said guide means and said threading means is adjusted relative to said needle.

12. Threading device as claimed in claim 1 wherein said holding means has a hollow casing portion for guiding said guide means; wherein said guide means has at one end an engaging portion for engaging said needle and at the other end a flange for engaging one end of said casing portion in said engaging position of said guide means when manual pressure is exerted on said threading means so that continued manual pressure causes movement of said threading means relative to said guide means to said advanced position against the action of said second spring means.

13. Threading device as claimed in claim 12 wherein said threading means includes a manually operable pushbutton portion located outside of said guide means; and wherein said second spring means is a compression spring located between said push-button portion and said flange abutting the same.

14. Threading device as claimed in claim 1 wherein said holding means has a recess located on the side of said holding means remote from said needle, and having a sharp edge so that a thread inserted into said recess is cut.

15. Threading device as claimed in claim 1 wherein said sewing machine includes a presser bar adjacent said needle; wherein said holding means include an arcuate attaching portion fitting onto said presser bar and embracing the same, an attaching screw for attaching said attaching portion to said pressure bar, a plate and a hollow casing portion slanted to said presser bar and said needle at an acute angle; wherein said guide means include a hollow guide member guided in said casing portion for movement between said inoperative and engaging positions, and having at one end a forked engaging portion for engaging opposite sides of said needle in said engaging position for accurately positioning said guide member; wherein said threading means include a manually operable member slidably guided in said hollow guide member and including a pushbutton portion located outside of the same, a threading member having at one end a hook portion, and pivot means for pivotally mounting the other end of said threading member on said manually operable member; wherein said first spring means includes a tension spring connecting said hollow guide member with said plate portion; and wherein said second spring means includes a compression spring located between said pushbutton portion and the other end of said guide. member.

16. Threading device as claimed in claim 15 wherein said casing portion is tubular and has a rectangular cross section; wherein said guide member is tubular and has a rectangular cross section matching said cross section, and four walls, two opposite walls of said walls having slots; and wherein said pivot means includes a pivot pin passing through said threading member and said manually operable member and having end portions located in said slots so that the ends of said slots are engaged by said pivot pin in said retracted and advanced positions of said threading means.

17. Threading device as claimed in claim 15 wherein said holding means includes a plate portion between said arcuate attaching portion and said casing portion, said plate portion having a recess and a sharp cutting edge bounding said recess so that a thread in said recess is cut, said plate portion having an elongated recessed portion guiding said tension spring and being located adjacent said casing portion.

18. In combination with a sewing machine having a needle with an eye, a threading device comprising holding means fixedly mounted on said sewing machine; guide means mounted on said holding means for movement between an inoperative position, and an engaging position engaging said needle, said guide means including a projecting stop portion abutting said holding means in said inoperative position; threading means mounted in said guide means for movement relative to the same between a retracted position and an advanced position; first spring means including a tension spring having one end attached to said stop portion and the other end attached to said holding means, said tension spring opposing movement of said guide means to said engaging position with a first resilient force; and second spring means connecting said threading means with said guide means and opposing movement of said threading means to said advanced position with a second resilient force greater than said first resilient force so that manual pressure on said threading means is transferred by said second spring means from said threading means to said guide means without deforming said second spring means, and moves said guide means to said engaging position whereby said threading means in said retractive position is aligned with said eye, so that continued manual pressure deforms said second spring means and moves said threading means relative to said guide means to said advanced position whereby said threading means assumes a threading position through said eye.

19. Threading device as claimed in claim 18 wherein said holding means includes a plate having an elongated recessed portion in which said tension spring is located.

References Cited UNITED STATES PATENTS 454,952 6/1891 Talbot et al 112--252 2,680,418 6/1954 Von Ullisperger 112-225 2,912,948 11/ 1959 Masuyama 112225 3,400,678 9/ 1968 Bennison 112225 FOREIGN PATENTS 18,901 1910 Great Britain.

RICHARD J. SCANLON, JR., Primary Examiner 

